Hello!
Anyway to write a program wich log me out of facebook after x minute inactive?
i know there is an option uncheck Keep me logged in but i want to edit the time

I don't think there's a 3rd party way to do this. Your login is a Facebook session that is controlled server side by Facebook. Unless you create a mouse click type thing..I don't think Facebook is going to allow you to mess with their sessions.

https://developers.facebook.com/docs/reference/android/current/class/Session/

Thats the android facebook sdk, there is a javascript / php sdk as well as some others.

Easy.. Get opera, right click -> Refresh every XXX seconds, use the facebook's logout url.. lol cheap n easy way, no program needed.

Seems like You and OP both have had issues with people getting on their Facebook in the past.. Lol

I bet you could do it with a grease monkey script.